As is disclosed in U.S. Pat. No. 4,462,267 of Shimano, which was issued in 1984, handlebars for bicycles are generally made from a metallic pipe and integrally comprise a bar body and gripping portions carrying braking control levers or the like through bracket members; the bracket members are generally separated from the gripping portions of the handlebar and are fixed thereto by the use of bands.
In 1989, in U.S. Pat. No. 4,829,847 of Modolo, ergonomic problems with conventional bicycle handlebars were discussed. At column 1 of this patent, Modolo disclosed that "The grip of a handlebar . . . is generally in the form of a tube having a single radius bend. The palm of the hand must thus adhere to the bend; it will therefore lie on the two ends leaving an empty space in the central part. This causes a thickening of the skin at the extremities of the palm, as well as skin irritations and in general increased effort and a contraction of the hand and wrist muscles. This state of tension jeopardizes driving safety and requires in general an increased effort on the part of the rider . . . "
The Modolo handlebar has met with a fair amount of commercial success, but it was not entirely satisfactory. Thus, as was noted in the 1992 patent of Borremeo, " . . . a selectively variable radius of curvature has already been proposed by several parties in the art, particularly for the central portion of the handle on which the palm of the cyclists hand is intended to rest. These solutions, and particularly that of making the central portion of the handle straight or almost straight, cannot be considered completely satisfactory from the anatomical and ergonomic points of view."
The solution provided by the Borremeo patent was to provide a handlebar with lateral handles containing alternating concave and convex sections.
Although the handlebar of the Borremeo patent arguably provides more comfort for those riders who frequently race bicycles in the common "racing tuck" position in which the riders chin is near the handlebar, it does not do anything for the vast majority of riders who use bicycles for primarily recreational purposes and ride in a substantially more upright position. These latter riders most commonly grasp the bicycle handlebar in the rearward facing concave portions of the handlebar while simultaneously resting their fingers on the brake levers attached to said concave portions.
In many of the more modern bicycle designs, the shift levers are mounted underneath the brake levers. Although this design allows the bicycle rider to shift and/or brake without moving his hands, there is a price to pay: the brake levers must be mounted further away from the concave sections of the handlebar in order to allow the shift levers to be disposed between the brake levers and such concave sections.
Many riders, especially those with relatively small hands and fingers, find it difficult to safely grasp the brake levers on such modern brake/shift lever designs. Even in those older models which do not dispose the shift levers underneath the brake levers, it is still difficult for many riders to comfortably and readily grasp the brake levers.
There is a certain minimum size required for effective brake levers, which size is dictated in part by the size of the mechanism required for the braking action and the minimum throw required for effective braking without having the brake lever hit the handlebar. Furthermore, because most braking mechanisms are a substantially standard size, it is desirable to provide a handlebar which accommodates such conventional braking devices.
One could, presumably, change the size of the handlebar to decrease the distance between it and the brake levers. However, a handlebar with too small a diameter would not possess the required tensile strength, would not be compatible with the standard brake lever fittings, and would not be comfortable. It seems that, for every problem solved by the modification of a standard handlebar assembly, at least one other problem is created.
It is an object of this invention to provide a handlebar assembly for a bicycle which allows riders with relatively small hands to comfortably and safely grasp the brake levers mounted on the handlebar, which is compatible with standard brake lever and shift assemblies, and which is at least as comfortable in substantially every respect as standard handlebar assemblies.